The unexpected transesterification between glycidyl methacrylate and 2-{[-2(dimethylamino)ethyl] methylamino}ethanol

In the course of some recent work involving novel metal chelating polymers,1 we identified monomer 1 as an attractive target monomer in view of its likely hydrophilic character, the presence of a substantial flexible linkage between the diamino ligand functionality and the methacrylate residue, and the likely ease of synthesis from commercially available glycidyl methacrylate (GMA) and 2-{[2(dimethylamino)ethyl]methylamino}ethanol (DAEMAE) via Scheme 1. While evaluating likely reaction conditions, we had occasion to perform one reaction without NaH and to our surprise were able to synthesize a product similar to 1 but clearly lacking the glycidyl derived spacer group in 1. Indeed, the analytical data suggested the product to be 2 (Figure 1), presumably arising from a transesterification reaction involving GMA and DAEMAE. Interestingly, we noted a similar reaction to this, between GMA and dextran, reported recently in this journal.2 This paper reports our efforts to understand the basis of this reaction and to probe its generality.